Hi welcome to Mailbag Monday Everyone's favorite segment: Yes I'm using the new bench this time Thought: I'd change it up Uh, experiment with the mailbag a bit. where I actually open them on camera here on the bench in front of me uh I'll give it a go, let me know if you don't like it, let me know if you prefer the uh previous format I'll just open them here and then I'll cut to the other bench where I actually do my existing shot and uh, play with the item once I've taken it out of the packet so you can see my reaction when I open it. That's the whole idea. Anyway, let me know.

Yes I have changed a bit of the background I've got a bit more instrument porn behind me, so let's get right into it. And for those who've been watching on Eev blog 2 where I did a couple of tests with uh exposure and this setup I'm actually using my uh Road video mic Pro shotgun mic instead of my wireless lapel mic that I normally do for a like a 2 m distance away from the camera. so uh, that's seems to be working quite well in this position anyway. uh I've now got 10 items to open.

Not sure if I'll get through them all on today's mail bag, but let's give it a go. This one is from Mark Richards and he's from Sylvania in Ohio where Chris Gaml is from. everyone's from bloody Ohio these days. Geez fellow blogger Martin Lon's there and uh, seems every man in his dog is uh moving there.

although I've heard Ryo are moving out of Ohio So there you go. Um so thank you very much Mark Let's have a look here. I know what's in it. Good thing about this is that I don't have to like hide all the uh, the dress anymore.

There's something in there. Don't want to throw it out. this is the digi key. uh recycled.

uh packageing it? course we're look looked at that before. This is great I can just throw it off the front of the bench. How efficient. Like efficiency.

Anyway, we got some. oh it's a 3D printed stand and it's a bat symbol. hang up. Got to be something else in here I reckon yep there is.

There's a couple of little boards. let's go to the other bench. First up, he's included a bat symbol here for San cut out of red Oak and it's 24 Karat gilded edges on it and a three with a 3D printed stand here. so that is pretty neat.

thank you very much. By the way, how do you Guild edges like that? I'm not into uh, doing that sort of thing. please let me know. But the major thing he sent in here is what he calls a power or or power or board.

Get it. power or power. Love it. Anyway, Um, it's a dual input uh, power supply that switches basically switches between different uh input, two different inputs and you can set a threshold voltage with this Uh pot here.

and then it automatically transitions between two different power sources. like you could have, say, a battery power source and a Mains power source and it'll the Uh Texas Instruments chip in here will automatically switch there. It is, uh, will automatically switch between both inputs. Um, when you get to a certain threshold, it'll seamlessly, so it'll continue to power your product.

Uh, for example, when the mains fails, it'll automatically switch over to battery or vice versa. Or you could have it solar powered, something solar powered, for example. then it would switch over to battery. And it's quite a comprehensive list of Uh functions here.

set by various Uh jumpers and pads on the Uh bottom of the board down in here and it can various configurations I Won't boil with all the details, but uh, it's rather interesting. Designed it for microcontroller Raspberry Pi and other low voltage projects and stuff like that. Now Mark wants me to critique the design? All right, let's go. And by the way, Mark is a beginner and uh, yes, this is one of his first Uh projects, so I'll go easy on him.

but uh. anyway. one of the first things I noticed is that, well, the pot is one of these huge ones like this. e.

these things are easily bumped. You know you accidentally, sort of, you know, brush it or move it about, throw it about the place I wouldn't have used that uh trimmer there as a set point for something like this I would have uh used you know, like at least a flat one that you need to get like a screwdriver in there to actually turn it. Anything that could be turned by hand. Not bad idea.

Now I can understand why you did this. uh two board Arrangement Here it's actually designed to be breadboard friendly so that uh it plugs in and yes, I have checked it. You did get the Uh pin pitch and everything correct, so thumbs up there. no problems whatsoever.

So does plug into a breadboard and then if you want to use it for say a Raspberry Pi then you just plug it into this Shield at the bottom and of course standard micro the existing micro USB input. Here you can have a secondary input coming in over here and then you've got of course the USB output which then goes off to your Raspberry P or other USB power product and then it can automatically select between the USB or some other wide in power source. But the other big issue that is immediately obvious is that the C metrical pin layout I can take this off, rotate it, and put it in backwards. So unless you've been very clever and actually wired it, uh, set the pin out so that it doesn't matter which way it goes in then W that's a bad move there.

You even need to stagger, uh, the pins or you know, plug up one of the holes or do something so you can't plug it in the wrong way around. and the next thing is the solder in so you haven't used nearly enough solder there. I Do applaud your use of minimalist uh, solder. Too much solder.

looks really ugly, but uh, you really haven't used enough there at all. Uh, always use uh, fine solder of course I believe you have been using fine solder like I use you know4 or 35 mm diameter solder really thin stuff but then feed it on there until the until you get a nice fillet on all of those joints. On the positive side, there's nothing wrong with your hand solded SMD stuff there. good work and as far as your uh, jump your solder jumpers on the back here I I Like solder jumpers of course it looks like you got the pad in the middle and you just bridge in this side here.

but what is L and what is p when I dig this out of my uh, you know junk box to go use the thing then I don't want to have to go back and read the documentation to figure out what that means. You've got plenty of silk screen space in there to put you know at least a complete word, a complete description. And the other good thing is that on your layout here, you have got solder mask between your individual pads in there. that's a big big, uh, beginner mistake.

a lot of beginners. just the solder mask expansion is too big and they don't have any solder mask between there or it's so very thin that the manufacturers can't uh, actually manufacture it uh, properly and then you can get solder Bridges and stuff between there. So excellent work on the solder mask expansion there now. I Do like the fact also that you've put the manual set resistors underneath the pot uh, you can't uh see it here.

but Mark has told me that he's done that I can see it on the PCB uh layout, uh, overlay as well. So if you remove the pot, then there's two Footprints under there for two uh set resistors so you can manually set and do away with the pot. So that's neat. I Guess if you really wanted to, you could have squeezed out maybe an extra uh Row in there and put these pins here and just had some of the resistors on the back.

uh, for example. but but uh, anyway, like you've decided to top populator I probably would have maybe populated all the parts on the bottom because you've got all room in there. You've got that height there available for all your SMD parts, so it kind of makes sense to put all your SMD Parts on that side. Don't worry about calling the board the top or the bottom or or whatever it's you know it makes no difference.

As long as you got all your parts on one side, then you could have a through hole part on the other side for example. and that's you can get really tiny footprint. so I think it could have even. It's quite small now, but I think you could have even made that one smaller.

Like you could have put the chip and all the other capacitors and resistors underneath this pot and then maybe moved this one row over and maybe even moved that one row over and just squeezed in the pot right on top. That would have been neat. and my other complaint has absolutely nothing to do with the board or the uh design whatsoever. It has to do with the fact that you haven't provided me with a schematic to look at and also I went to the website which I love the name Mouse Bite Fever um on GitHub and there are no PDF schematic files available for easy viewing.

You've only got the Eagle board and uh schematic files and I don't have Eagle in my system. I'm not going to install Eagle just to view a schematic so that's just a note to everyone is doing: Open Source Hardware projects like this. There was actually a thread on the Forum about this. somebody complain about it or or one of the threads just went a bit burko on this exact topic: not providing a schematic in a you know, an easily viewable PDF format and I think that's pretty essential.

And you know if you're going to go to the effort to do and release an Open Source Hardware product, just you know, make the schematic easily viewable. Not everyone has Eagle or whatever on their system, and for those who haven't seen inside this chip before, they are quite neat. They're not AOL volage regulator or anything like that. They're basically just a dual switch to automatically switch between the two inputs here.

and that's exactly what we're doing. Two uh, Power mosfets in there. Not huge power, of course. it's only uh.

this particular device is only designed for low power stuff. but I Noticed on Mark's GitHub that he's done another design which uses an external mosfet which allows for higher voltages and higher currents Anyway, two internal mosfets which are just basically switched off and on. but it ows some extra functionality. It's got a current limit adjust here set by an external resistor and I don't know Mark Didn't mention anything about the current limiting, so that's probably one extra thing I would have done on here.

Maybe if you had room, I' at least put a footprint for the current limiting resistor I'd Maybe even if you had room. maybe not on this design, but if you did, I'd have like a couple of uh dip switches on there. maybe a little two, or a 4-way dip switch or something like that with four different value resistors and the user can just like choose four different two or even just two different Uh current limit settings. that would, uh, that would be nice.

Anyway, it's got building thermal cutout and all sorts of stuff like that and uh, really, quite nice dedicated chip for switching between two input sources here and dead. easy to use. I mean you basically feed the voltage in, you, just decouple it, feed the voltage out. you might have to decouple the output and but H not much else.

Bob's your uncle and as far as a PCB layout goes, I don't mind it at all. You got some right angles there, they just going to FL fall off the quarter. Jeez, some people take that seriously. Unbelievable.

But yeah, we can basically switch between the top and the bottom there. Look at that. neat and uh, something that I immediately always look for on designs like this is. well.

do you have enough uh V stitching in here to get your ground coupling over? because your current is not flowing through here at all. It just stops. That's just some flood fill. see how flood filled this? It's not bad and uh, but basically you've got um, your ground coming across here, going through up through one via there and jumping across to another via down in there.

So you know as a general rule of thumb, one via good enough for you know, half an amp, something like that. So on this design, which is designed for uh, low current applications, yeah, it's going to be good enough. Just as a matter of course. maybe I would have thrown in an extra via, but probably not on this design, so that's fine.

Um, and yeah, not a real issue. but as I said, I would have just m Ed all of the parts on the bottom SMD Parts on the bottom underneath the through hole trim pot and then uh, did it that way. So you still get the advantage of being able to mass manufacture this thing because your components are, only, well Mass manufacturing. You still manufacture it when it's whether either it's single sided or double-sided component loaded.

but the fact is, it only has to go through one pass in the SMD machine if you were Mass manufacturing this. uh, which isn't the case, but if you were, then good practice dictates you put all the parts on one side and the through hole part. well, they would just hand solder those anyway. So and that's a potential way you could have, maybe you know, made the board you know, that wide or something like that.

perhaps at a guess I don't know I Haven't done the actual Um measurements and things like that, but hey, that is a good first effort for an Electronics beginner I Like that good on you Mark. Thanks for sending that one in and if you want to check out his project, it's Github.com Mouse Bite Fever. Staying Alive. Staying Alive Staying alive.

Next up we have one from the Old Dart Yes England and uh, this one comes from Mr Damian Nagel Good on you Damian And uh, let's crack this sucker open and see what we've got inside. Aha I like and look at this I'm liking the look here we go. Oh no away. Yes! Casio Fx7000 GB Awesome! GB Great Britain Hey Beauty! Unbelievable Damien Went and married a Bloody Palom.

He's actually an Aussie and he married a Pom and that's why he's over there. but he's back now. Apparently he has returned anyway. Um, he this is what he actually paid for it250 p Awesome in a thrift shop.

Unbelievable! I Always wanted one of these babies. the Fx7000 I lusted after this I never had this one and uh oh it's just awesome. Look, you can get a S wave and this is prev vpan rubbish too I think so yeah Beauty I I Hate Vpam Vpam is stupid and there's a nice postcard of the Clifton suspension bridge I Haven't seen that one but uh I have been over the world's longest suspension bridge which or second longest or whatever. it was the world's longest at one point and that was in.

that's the Humber Bridge I Can't believe what I Can't remember what town it was in, but it was um on the east coast south of Bridlington where I uh stayed for a couple of weeks so it was like yeah, like half an hours drive. uh from there and then we have um Bristol awesome. Have not been to Bristol that looks very nice I'd love to go back to England it'd be fantastic. There we go Somerset and a the brist Bristol Channel Terrific.

Haven't been there I've been to Bath which is around here somewhere I think yeah, that's right. Bath is like out here somewhere Southeast is Bristol so slightly off the map anyway. I maybe we sort of scooted through the outskirts of Bristol I can't exactly recall, but yeah anyway. been to Bath Loved Bath.

Fantastic. Wow there it is. Check that out that's in really good Nick I Love that that is fantastic. It needs some batteries apparently.

doesn't work. um but yeah. made in Japan um CR 2032 Three of them. no worries.

I Can get that sucker powered up no problems whatsoever. And as far as um, keyboard key layout goes, not bad. Dedicated engineering button? That's what you need. Dedicated inverse button.

That's what you need as well. and uh, doesn't have dedicated XY Swap button. No, that's a bit of a bummer, but doesn't have a it's got dedicated squared button which is excellent. Um, but yeah, shame it doesn't have a register swap dedicated key unless I'm missing it.

Actually, this is rather interesting that it's only got two screws on one side here and then has the uh tabs on the other side, so that's rather unusual. There You Go Notes on battery replac switch power off blah blah blah blah blah. Let's whack some batteries in. That's a rather, uh, unusual usual battery compartment.

just goes in there and just slides in and just hooks under there. like that. It's actually rather effective. I Like that.

All right, let's see if we can power this Relic up. it's not that old. Oh, there we go. We have to seriously, uh, do some contrast uh there on the screen.

but there we go. we're in like Flynn Yeah, it's certainly not the best display there look at that you know you turned up decent contrast and then then you get all the uh stuff on the back back there so it's not. It's not terrific screen that's for sure, but that's what you get with DOT matrixes of that era really. And according to Wikipedia, this was the world's first graphin scientific calculator back released back in 1985.

Oh, you know what else happened in 1985? Yeah, when this baby hits 88 M hour, you're going to see some serious oh no damn it. I was wrong. Even though it's not, it doesn't use Vpam. Visually perfect algebraic method.

It uses true algebraic mode. So basically what that means is if you enter like you know, 10, you can't just go in there and hit sign like that. It doesn't work. It gives you a syntax area.

You've got to actually do it as written. So you got to go sign. It's the operator first and then 10 like that to give you the answer. And that's great if you want to, Actually, you know, evaluate a big long expression you're entering it in and you know, Yeah, okay, it's it's fantastic.

But just for every everyday day to-day use I Prefer the oldfashioned method oh vpam bloody hell and forgive me for shooting on this angle. but it's just easier to get a display up and view the Uh keyboard at the same time. Now, if you wanted to graph something, it literally was as easy as this graph sign for example. And bingo, it'll draw your sign wave.

Look at that. Uh, these were just the building functions. Of course you could do user uh defined functions, but yeah, look, we can just go. whoops.

We can just go graph. say 10 X Look at that. Here it goes: It's Going Up and Up Up and Up and Up. Then you can do stuff like use the Uh Trace mode here and then you can just cycle through.

You probably can't see it, but there's a tiny little dot somewhere or inverse dot somewhere on that waveform. You can scroll it across and you can actually get the value off the graph. One of the main disadvantages for your user defined functions: it wouldn't autoscale the graph. uh, for you.

So you had to go into the range mode here and then actually enter in your ranges manually of your graph. But you know, Apart from that, hey, pretty useful. And this was groundbreaking when it first came out. Oh, you graph your own functions.

Unbelievable! I Guess the one Saving Grace of this interface is that you could actually use the engineering mode. For example, we can go up minus 3 for example. like that and then we can actually take the calculator result and then we can cycle through it like that in the engineering mode. So yeah, that was okay, but then, like you know, you couldn't just suddenly take that result and then just invert that.

you had to do that and then press. XE It's like for your average one off day-to-day calculations, that's just annoying. Too many button presses and you also sending one of these ideal voltage detection sticks. Everyone should have one of these.

I've got a fluke one. I've also done a tear down of this one, but he says this one uses a different board to the one I tore down. so let me crack this sucker open and uh, see if we can't have a quick squee at that. There we go I can't remember I haven't watched the previous video I can't remember but that's supposed to be a different board and Chip to the one I tore down previously so thank you very much Damian this is just awesome I Love calculators and this one is a classic I always got it wanted one and this is going straight to the pool room.

next up we have one from you guest it dland Germany we always get one from Germany I have a huge contingent of German viewers I'm big in Germany for some reason so hi to all my German viewers thank you very much and this one is from um fck sorry, can't pronounce it at all in Uh Orenberg in Germany I sorry I can't pronounce I'm hopeless at pronunciations but anyway, let's whip this one open and let's have a look what you sent so thank you very much F I presume that's your first name Frank Good on you Frank Here we go we have a letter from Frank um I have the Metro wat Unior A43 is crusty uh yes. In a previous mail bag we looked at the uh, there it is Tada the unior a 43. There we did that in a previous uh, tear down and mailbag. this is an Omer it's produced in the former German Democratic Republic of East Germany in 1989 let's have a look.

We have our oh oh oh good look at that classic yeah I'm going to walk around look I'm going to be uh all modern and trendy with my uh leather multimeter pouch. look at that. Oh just whip it out here we go. Just going to whip out my Omer except for the fact that I can't get it out and I don't need to because it opens.

Whatever smell that is it opens like that. Look at that. Beauty There you go and it uses a what's this 2 R10 battery. Never heard of it.

Um anyway, the German Democratic Republic East Germany 1989 Oh my goodness. Look at that. Oh that is crusty as oh my goodness, does anyone remember using one? I Mean you know 1989 is pretty bloody recent and it's just an Omer That's it. Nothing else.

Not even a multi. Can't even call this one a multimeter because a multimeter measures multiple things. usually you know, Vom Volt, Ohm meter. You know, at least it measures volts and ohms and ohms only goodness.

Actually, you take it out of the box and it is rather cute. Look at that. it's I Rather like that it's got The Binding posts and the banana plugs on top. No holes in it to uh, feed your wires through.

but uh, that is. that is really quite cute. Look beautiful a look at that back on it, you can see through it. We got to crack this open.

not that it's going to be much in it. Look at the bizarre range selection switch here. it's just got dots. I Mean you think? they? they put the dots on there? They think and then they've got the dots Associated on the display I Think they could have printed them in there, but maybe they got different models with different uh, maximum scales or something like that.

Anyway, down there is times 0.1 of the scale so that' be from like that would be like 10 ohms there. Um instead of 100 and over here it' be Time 1 so that would be 100 ohms there and time 10 all the way over here. so that' be 1K 2K There's no even onoff button on this thing. You just you know, have it switch to the range and it only works when you actually do the probe.

the I can't even zero that thing properly. So uh, there's something wrong. It's completely Cactus and there's the battery holder down in there. half of that 2 R10 battery.

Whatever the hell a 2 R10 battery is. But yeah, look at that. Anyway, four screws here we go. so there's a look inside the movement and by the way, the uh, this on the back here on the bottom I mean would be the uh zero Ohms adjust of course and uh but yeah that oh oh there we go.

We managed to managed to bring it back out. we can actually Center that we can actually adjust that right to Infinity There we go. Woohoo she's back in action. And of course then we use the zero Ohm adjust on there.

so if we can hook up a battery to it, this puppy might still work and I powered it up here and well, well, I can get it to deflect but basically I can't get the uh zeroed oh function to work at all and well, it's nowhere near it and it just doesn't seem to really work so what fail and it's not really worth taking apart any further. take that plate off. I mean down in there there's a couple of resistors and basically, uh, bugger all else, but that's that's pretty much what you'd expect out of an Omer like this I mean you know we got our size of big magnet in there which sits around our coil, our deflection coil, and uh, well, you know it's about it. It's got a trimmer down here and well, not much at all.

And the original manual? look at this. there we go. for those who can read it. I'm sure a good uh, probably 1third or quarter of my audience can anyway.

and fantastic. There you go. That's who makes it. VB I would even try and pronounce that, but there you go in: uh Linen Strawy in no, that's Street sorry Linen Strawy 244 244 Linen Strawy is a uh street is it not? and uh, there we go.

We have some specs. couple if there's no schematic in it ripped off there it is. 5th of March 1989 I Guess there was still a call for this thing in 89? Go figure. Tested by number three I think what proofer means I'm assuming um so there you go.

thank you very much Frank that is uh I wouldn't say crusty I'm bit. um minimalist um would be probably a term I would use, but it's kind of cute. I mean it's got a it's got a nice case on it's, really quite rugged I'm sure it could survive a fair bit of abuse actually and probably has big as well. it's it seems to be nonfunctional, but there you go.

Ah thing of beauty Joy forever and this one looks like it's from Anonymous but look, it does have my picture on it. Woohoo! Look at that! Fantastic. All right, any resemblance great anyway. thank you Anonymous person.

uh local of course if you don't know the Australia Post bubble wraps um from Mount local post office that's hearing not too far from here and uh way hello oh there we go Doo we have a letter greetings Dave and it's from Mike I've included for your Ted down a fault finding pleasure an old Sharp Zq 5200 electronic organizer. Yes, a whopping 64k of memory. Um, he received this from his father as a child when he was working as an electronics engineer at Sharp in Hywood. Yes, Hunting Wood is just here in Sydney just down the Great Western Highway there out west, uh back in the 80s and '90s I wonder if they're still there I haven't driven past there in years, but there used to be a huge sharp Factory uh on the Great Western Highway out in Western Sydney here.

Geez, I started working 1989. how young are you Mike Jeez, if your dad worked there in the 80s and '90s Um, there you go. Certainly seen better days. Well yes, it has.

Look at that. I use one of these. It was a small, much smaller, thinner one. It was even thinner than half that.

maybe? Yeah, it was like a third of the thickness of this thing and it was a I think it was 32 or 64. Um, but I didn't get this one because I wanted something really. uh, slim line and uh yeah. I remember these things and I actually used it back in the day I had, uh, you know, used it as an address book and stuff like that had people's uh, contact details and phone numbers back then before the days of mobile mile phones.

Of course you know you'd have these things and you keep diary appointments for my very hectic social life as a nerd. Yeah, right. and uh yeah, these were, um, quite useful back in the day and uh, they I never lost any info from it. They always had a a primary battery and a second, uh, battery backup.

uh battery. but uh, you could and then a super cap on top of that. There we go, it's still in there. See 2, three, 2, three goodness.

I'll get it right eventually. CR 2032 batteries and uh, normal operation. Yeah, this one had the mode switch where you had to actually, uh, put it if your certain location if you wanted to replace the sucker and these battery replacement mechanisms were actually work quite well in normal operation. look with the tab switch there.

You couldn't physically slide this across like that to remove these batteries here. If you wanted to replace the and if you wanted to get and this one the So This: these are the operational batteries. This is the battery backup one here. You couldn't physically slide that so none of them could fall out.

You couldn't replace them. If you wanted to replace the backup battery, you had to move that over there and then you could slide that out. You still couldn't get these out. If you wanted to replace the main batteries, you slide that down and bingo you can pop the batteries out.

It's a neat system. idiot proof so that your Muggles operating these damn things can't uh, screw it up and lose all their contents and of course cuz these were kept in SRAM Back in the day they weren't uh, you know, kept in Flash or anything like that. All right. I've replaced the batteries.

Let's see if this sucker Works no, it's a it's a fail might have to there a reset switch on this sucker. No, it doesn't even work after pressing the reset switch It's Cactus All right. So let's open this. I Taken off the uh, peeled off the back cover.

It literally just peeled off. It was just stuck on the instructions there and uh, of course this thing is. uh, it's not going to be much in here. There's going to be a basically a single chip solution pretty much plus my uh, external memory.

There will be an external 64 or dual 32k s RAM and uh, kilobytes that is. and that's probably uh, all she wrote, look at that. We got some I don't know. Do I have to peel that one off too? Probably a couple of screws under there? Yes, uh.

Sharp pretty much owned the organizer business back in the day. I'm not sure when the Glory Days of the organizer started and ended. If anyone knows, it's probably on Wikipedia But If anyone knows, that would be, uh, interesting to find out. Oh I think got another bloody screw up under here.

Maybe I could just break that sucker. but uh yeah, Sharp were pretty much uh. number one. The Sharp organizers flooded the market.

They had so many different models and I uh I I really liked the uh user interface on them I thought it was uh, really quite good and uh, there we go. Yeah, quad flat packs and uh, memory ROM single chip solution. chip on board. job there doing something? So let's and that's our expansion interface over there that Mike was talking about the serial, uh, expansion or some other expansion interface right on the end like that and uh, yeah, it's about all she wrote.

there's our 32 khz Crystal Now check this out. What? I At first glance I Thought this chip on board device here was actually uh, you know, mounted on the main board. but it's not. It's on a secondary board here and then that board is surface mount solded onto here.

almost like it's I Don't know. Not really an afterthought, but gee, I don't know. And then the Um 32.768 khz watch crystal was then just, uh, you know, tacked onto a couple of the pins of that chip here. So that's got to be more than the just the real time clock chip.

It seems to went to a lot of trouble for a real-time clock chip. I Mean this is not hugely old this thing. So anyway, we got ourselves. yeah, there we go.

Uh, 27c 256. they're our ROMs actually. so that's our firmware and uh, there's our SRAM up there. and really, there's not much else to it.

Here's one of the expansion ports on the side here, and uh, that's just a Serial expansion. Port Couple of look, they got an insulated pad under there and they've gunked down a couple of these chokes here. Not sure why they've done that. they've bodged on a cap here look and they've intentioned to detail they actually put don't know why they''re bothered, but they have.

They've put a some heat shrink tube in over one side of that and there's the other uh expansion Port underneath there. but as you can see, there's buger o' inside these things I mean there's you know na all in them and it's all in the uh firmware and of course all the LCD uh driving stuff is all going to be up in here so that'll be you know, the big doc Matrix uh display that's going to have um, its own so maybe we can crack that open and just very quickly and have a look at the uh LCD drivers up there. Nothing exciting though. well that's interesting I expected.

uh another PC Ofb in there. maybe with some quad flat packs, uh, driving that board and a uh zebra strip or something going in there. but we have some uh you know, chip on Flex here and uh, some hot bar stuff going on there and uh, there we go. well we got another one there we go and so they're on, uh on the flex membrane and that's pretty much it.

and of course this would be a Sharp LCD cuz sharp were I think still are huge in LCDs So there you go. They really know how to manufacture LCDs sharp and they would have uh, been able to churn those out for pennies and that's you know, it's quite Advanced manufacturing which uh you know goes into getting uh, those sort of things right? So that is about a she wrote. Then we got keypad going down there and not much else. So there you go.

It's a bit of a mess, but thank you very much Mike for sending that one in. These were these pocket organizers were huge. so if you do know the uh, lifespan of these things when they actually you know died and how quickly they die I think they did die a pretty quick, uh, death in the end. but I I certainly had a sharp one and I've probably still got it somewhere and it probably still works.

probably still got the original backup battery in there. there. these S Rams are ridiculous. You know it's B ridiculously low currents.

basically the shelf life of the battery and these things. and yeah, they great. Back in the day and lucky last for today. Yes I still got two, four, five left.

so I'll leave those for next mailbag. Monday which hopefully should be next week. can't do 10 one episode. it gets pretty ridiculous.

Oh this one's from Aiden Senior once again. Aussie um envelope he's from Stockton once again in New South Wales so thank you very much Aiden What do we have? Oh another bloody mobile phone. You know how many bloody mobile phones I've got? Oh unbelievable. This are tiny though.

a little Motorola thing. man they don't make them this small anymore and well, yeah, I Can see why. Jeez, you can almost swallow that thing. Unbelievable.

And what else have we got? It's a universal dimmer. Why? there's a note all Dave I Thought this Clipsal Speed Controller dimmer would make an Inter in mini tear down. I Find them quite fascinating considering their size and the fact that it can drive 450 Wats? yeah, it's probably going to be very little. uh, well, there has to be by their nature.

Uh, very little loss in there. Uh, they have to be quite efficient. Um, just you know the sheer numbers. You can't drive 450 watts and be 90% efficient.

Because if you're 90% efficient, you dropping you know, 45 watts in this thing not possible. So they're incredibly efficient. Uh, this particular one was scratchy I Keep love the blog keep of the good work I Watch your episodes with frequency until it megaherz. What? thanks Aiden Yeah, I've never uh, used one of these before and I don't uh, particularly know what's in them but there is a board.

look at the bottom I Mean this one has a Uh has a nice big pot on the back. that's what he said was uh, scratchy and uh, there's a fair bit of surface mount integration in that Ccle. Let's crack it open. Wow, these little up is a Chalker block.

Look at this. I mean we got looks like we're going to have double-sided load on. Look at this little Cube construction board. So three boards? we're going to have probably double-sided load on it.

There's a lot going on in there, and that's actually fairly common to. uh, butt boards together in this configuration. like that, right angle boards. I've done that a few times myself, especially inside slots.

You can actually cut out slots inside a board and then Mount at right angles like that and have the solder on. uh, both sides. you can actually get a pretty good, uh, right angle board out of a main just sticking out of a main board there. So they got just the one tab on here, so we're going to have to desolder that and I'm trying to prize this thing open and these bastards are solded shut.

Unbelievable. What a turd. Well, there ain't nothing you can't fix with a drill. Here we go.

Woo woohoo, we're in. So there you go. That's what's inside one of these puppies. and uh, there's our pots still on there.

I Just cut the uh pins off the top of that to get one of the boards out. and these two boards here. Of course, they were soldered together like that. I Had to get my solder sucker and suck out all those pins before I could even get that board out.

And um, yeah, so they're actually double-sided. Pretty densely populated. Uh, double-sided load there. Lots of little uh, six pin, so 23 packages.

I Don't know why they need to go to all that trouble. Anyway, here we go. Here's the Uh. here's where we get all of our uh, switching and efficiency from.

We' got two mosfets here. They were riveted into the sides here. There you go. They got some pop rivets there.

so I had to drill those out and uh, let's take a look at that top board. Once again, double-sided load? Not surprising. Here's our Main's input here. We've got our four Bridge rectifier diods.

so they're forming a bridge rectifier no doubt. Uh, that's not surprising. And then we've got a cap on top of there. And of course, that cap is a quality, uh, Reefer brand one there, so you know, no drama there whatsoever.

You'd expect these to be high quality of course. And then there's an E3f uh, 250 volt rated 115 C thermal cutout that's from microtherm. They make nice little thermal cutout devices. so BAS Basically, if in the inside of here I mean it's not thermally bonded over here.

but basically, if the inside of that uh case pretty much gets to 115 C then it's just going to just going to cut the mains off completely. So little safety feature and no surprises for guessing. We've got some mosfets in there stand pretty standard ones: 20 n60 C3 Well, standard for this sort of uh application that requires the, uh, massively high efficiency. cuz you know that's not not much of a heat sink there.

So you really, you know these things have to be incredibly efficient. Um, as we said before, 450 wats so you know you can only even at 1% you know 99% efficiency. That's still 4 and2 Watts inside that tiny little beast there. So let's go to the data sheet and no surprises for guessing that you get sort of.

you know the world's best RDS on uh, which is the on Resistance when the mosfet is switched on in a To220 package, the world's best one. Don't know if that claim is actually true, but RDS um on19 Ohms there 650 volt VDS Rated 20 amps These things are a beast and I'm they're probably not cheap either I Don't know what the digi key price is, but yeah, these puppies wouldn't be extreme. Dvdt rated oh periodic Avalanche rated oh beautiful. Look at the specs so thank you very much.

Aiden That's a rather little interesting in mini tear down as you suspected it would be. These things are chocka block I Can't believe how much you know why they need all of that. Gee I don't know. but uh, if anyone has a schematic for one of these puppies, it'd be really interesting.

I Mean we're not going to get part numbers off these. uh, really, you know, easily obtainable part numbers off these little six pin so 23s and stuff like that. So if anyone does have a schematic for one of these puppies, uh, please link it in, let us know. So there you go.

This has actually been a very lengthy mailbag Monday even though I only opened half my stuff. Anyway, please let me know about the new format with uh, you know the Talking Head shot uh on camera if it's any good. and if you like that of I'm actually shooting this with uh, two different cameras here. by the way, there it is.

So I got my uh got my B-roll camera that one was the one I was shooting the material with and there's my uh Road video mic uh, shotgun video mic Pro and uh, just sit there. it actually works pretty well I Just you know, soon as I'm done shooting something here I come over this bench which has my uh uh Canon HF G10 my main camera and I shoot all the stuff on the bench as I normally would. so let me know if that's any good. If you want to discuss it, jump on over to the E blog forum.

And as always, if you like mailbag Monday please give it a big thumbs up. Catch you next time and.